1. Field Of the Invention
The invention herein pertains to fabric retention during commercial embroidering and sewing and particularly pertains to devices for holding fabric taut during operations thereon by multiple head sewing machines.
2. Description of the Prior Art and Objectives of the Invention
Pantograph-like devices are frequently used on commercial multi-head sewing machines whereby emblems, logos, names and other designs are simultaneously applied to a number of shirts, jackets or to previously unsewn fabric. U.S. Pat. No. 5,228,401 demonstrates a sewing apparatus having a T-shaped pantograph which for example can be used with a rectangular frame to hold fabric on all sides during stitching or embroidering. U.S. Pat. No. 4,495,876 demonstrates a rectangular frame for holding cloth in place during multiple head sewing operations. Prior fabric holding frames have employed different methods to maintain fabric taut and certain manufacturers employ a conventional frame device as shown in FIG. 5 herein which utilizes a bulbous projection and a removable spring steel clamp. In use, the edges of the fabric to be stitched are placed over the bulbous projection around the frame and several spring steel clamps which may each be a few centimeters in length are urged over the fabric laden projection to maintain the cloth on the frame. The spring steel clamp and radius of the projection are designed whereby the clamp can be removed and replaced manually on the projection quickly by inexperienced sewing personnel, yet tight enough to adequately secure the fabric edges under adverse sewing conditions. As would be understood, in commercial operations, twelve or more sewing heads may operate in unison on the fabric which is stretched over the frame and in many patterns, tremendous pressure is applied by lock stitching thousands of stitches in a very small space. Thus, extreme pressure is applied to the fabric, sometimes, actually pulling the clamps free of the fabric and projection. When this occurs the sewing operation must be stopped and oftentimes the entire pattern resewn on new fabric with great loss of time, labor and materials. If clamps are designed to securely hold the fabric under the most adverse sewing conditions as frequently occur, the clamps are generally impossible for the average worker to manually, easily remove and replace when needed. Hence a dilemma exists in fabricating the spring steel clamps to provide enough tension to properly hold the fabric, but allowing sufficient resiliency for manual removal when replacing the fabric for the next cycle. Another concern for manufacturers of standard fabric holders relates to the particular fabric being sewn. Certain fabrics are thicker than others and the tension of the spring steel clamp must be such that it will sufficiently hold both thick and thin fabrics. The clamp manufacturer must insure adequate clamp tension to securely hold the fabrics yet the sewing machine operators must manually, quickly remove and replace the clamps at the beginning of each stitching cycle.
Thus with the disadvantages and problems associated with prior fabric holding devices, the present invention was conceived and one of its objectives is to provide a fabric holder for multi-head sewing machines and a method which grants secure fabric retention and easy manual usage by relatively unskilled personnel.
It is still another objective of the present invention to provide a means for holding fabric which includes a wave-like crest projection and a clamp with a complementary receptacle for receiving the wave-like crest projection and fabric therein.
It is yet another objective of the present invention to provide a frame for a multi-head sewing machine which utilizes the fabric holder as immediately described above.
Various other objectives and advantages of the present invention will become apparent to those skilled in the art as a more detailed description is set forth below.